Social-categorical knowledge is partially grounded in proprioception. In Study 1, participants describing "hard" and "soft" politicians, and "hard" and "soft" scientists used different "hard" and "soft" traits for the two groups, suggesting that the meaning of these traits is context specific. Studies 2 to 4 showed that both meanings were supported by hard and soft proprioception. Consistent with political stereotypes, perceivers viewing faces while handling a hard ball were more likely to categorize them as Republicans rather than as Democrats, compared to perceivers viewing the same faces while handling a soft ball (Study 2). Similarly, consistent with stereotypes of "hard" and "soft" academic disciplines, perceivers were more likely to categorize photographs of professors as physicists than historians when handling a hard versus soft ball (Study 3). Finally, thinking about Republicans and Democrats led participants to perceive a ball as harder or softer, respectively, suggesting that simulating proprioception might aid social-categorical thinking (Study 4).